The present invention relates to steel bar manufacturing process and more particularly, to an U/Z-shaped steel bar manufacturing process, which is practical to make U/Z-shaped steel bars having punch holes of different punch patterns.
FIG. 1 illustrates an U/Z-shaped steel bar manufacturing flow according to the prior art. The method comprises the steps of (1) material supply where a steel sheet material 90 is let off from the spindle of a material rack 91 to a roll forming mechanism 92, (2) roll forming where the steel sheet material 90 is rolled into a continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 by the roll forming mechanism 92 (see FIGS. 2 and 3), (3) punching and cutting where the punch die 931 of a hydraulic punch press 93 is operated to punch the continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 with punch holes 9011 or 9021 (see FIGS. 4 and 5) and then a hydraulic cutting die 932 is operated to cut off the continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 subject to the desired length, and (4) conveying where a conveyer (not shown) is operated to deliver finished products backwards for packing and further storage. This U/Z-shaped steel bar manufacturing process still has drawbacks as follows:
1. When punched by the punch die 931 of the hydraulic punch press 93 or cut by the hydraulic cutting die 932, the continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 tends to be deformed, resulting in poor quality of finished product.
2. One punch press can only punch the continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 with a predetermined pattern of punch holes 9011 or 9021. For punching punch holes 9011, 9012, 9013, 9014 of a different punch pattern (see FIGS. 6˜16), the continuous sheet of U-shaped steel bar 901 or Z-shaped steel bar 902 must be transferred to another punch press. Therefore, the manufacturer may have to prepare multiple hydraulic punch presses and punch dies for punching different punch holes of different punch patterns. It requires much investment cost and installation space for multiple hydraulic punch presses and punch dies.
The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide an U/Z-shaped steel bar manufacturing process, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the steps of: (a) material supply, (b) material flattening, (c) material punch-hole punching and length-cutting, (d) material shape forming through a roll forming machine, (d) finished product straightening, and (e) finished product packing. This manufacturing process is simple and efficient, preventing deformation of finished product and maintaining the quality of the finished product. According to another aspect of the present invention, the punch press has position-adjustable punch dies. By means of adjusting the position of the punch dies, the punch press is operated to punch the steel sheet material with punch holes subject to the desired punch pattern. According to still another aspect of the present invention, one single punch press can be operated to punch the steel sheet material with punch holes of any of a plural punch patterns, the invention saves much equipment cost and installation space.